/* 容器样式，设置渐变背景及关键帧动画 */
.sosd-container {
    width: 100vw;
    height: 100vh;
    /* 初始渐变背景，可根据喜好调整颜色 */
    background: linear-gradient(120deg, #f6d365, #fda085);
    /* 应用背景渐变动画，时长 20s ，线性过渡，无限循环 */
    animation: gradientAnimation 20s linear infinite;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

/* 背景渐变关键帧动画 */
@keyframes gradientAnimation {
    0% {
        background: linear-gradient(120deg, #f6d365, #fda085);
    }

    25% {
        background: linear-gradient(120deg, #84fab0, #8fd3f4);
    }

    50% {
        background: linear-gradient(120deg, #a1c4fd, #c2e9fb);
    }

    75% {
        background: linear-gradient(120deg, #ff9a9e, #fad0c4);
    }

    100% {
        background: linear-gradient(120deg, #f6d365, #fda085);
    }
}

/* 标题样式及进入动画 */
.sosd-title {
    color: #fff;
    font-size: 3.5rem;
    opacity: 0;
    transform: translateY(20px);
    transition: all 1s ease;
}

/* 标题显示时的动画效果 */
.sosd-title.fade-in {
    opacity: 1;
    transform: translateY(0);
}

/* 按钮样式及进入动画 */
.enter-btn {
    margin-top: 1.5rem;
    padding: 0.6rem 1.2rem;
    font-size: 1rem;
    background-color: rgba(255, 255, 255, 0.2);
    color: #fff;
    border: 1px solid #fff;
    border-radius: 4px;
    cursor: pointer;
    opacity: 0;
    transform: translateY(20px);
    transition: all 1s ease;
    transition-delay: 0s;
    /* 初始延迟，通过动态类控制后会覆盖 */
}

/* 按钮显示时的动画效果 */
.enter-btn.fade-in {
    opacity: 1;
    transform: translateY(0);
    transition-delay: 0.3s;
    /* 让按钮动画稍晚于标题，可调整 */
}

.enter-btn:hover {
    background-color: rgba(255, 255, 255, 0.3);
}